Telegraph or teletyper plant



Sept. 22, 1931. V w A, JIPP 1,823,978

TELEGRAPH OR TELHTYPER PLANT Filed Feb. '18, 1929 xi 0 *1 l iwi? w N F7%; F" a *9 y I w a I Y v izxfrai Patented Sept. 22, 1931 UNITED STATESPATENT OFFICE AUGUST J'IIPP, OF SPAN'DA U, BERLIN, GERMANY, ASSIGNOB '10SIEMENS &

HALSKE, AKTIENGESELLSCHAI'T, OF SIIMENBSTADT, NEAR BERLIN, GERMANY, A

CORPORATION OF GERMANY TETIEGBAPK )3 TELETYPER PLANT Application filedFebruary 18, 1928, Serial llo. 340,888, and in Germany February 18,1828.

The invention relates to improvements in the connection over a specialline not used durin the selector or telegraph operation, in or er toenable the necessary differentiation to be made between the currentimpulses for the various purposes (selector, telegraph, selectorresetting impulse) used in the operation of the plant.

To enable the resetting of the selectors to be made over the lines usedfor the selector and telegraph operation, according to my invention theresetting of the automatic selectors takes place by impulses. theconditions or nature of which (such as the type of current, frequency)are difl'erent from those of the selector or telegraph currents.

In this way it is possible to manage even with two conductors only of anordinary telephone cable line, audio frequency or subaud1o frequencycommunication bemg preferably used in view of the telephone service,which also allows multiplex utilization of the lines.

The different condition of the selector resettin currents may, forinstance, be attaine by employing alternating'current'in contrast withthe direct current of the seoperative or rest position temporarily topass into the operative or working position, a difference in theduration of the impulses may be effected by bringing the armatures afterthe termination of telegraphic traific i. e.

after the return into the inoperative p0si-' tion permanently into theoperative position, whereby a permanent im ulse is given, which isutilized for the tripping of the resetting relay and, if necessary ofother parts of the apparatus, such as a switchgear controlling thedriving motor. The armatures are thus brought into a false position ofrest differing from the true position of rest. Since polarized relaysmainly come into account, the armatures remain in the falseposition ofrest even after switching ofl the total operating current and the givingup of this pos tion when the current is switched on again may also beused for releasin operations on the receivin side. The t rowing of therelay from the alse into the true position of rest is preferablyefi'ected by a condenser impulse released on switchin on the motor ofthe telegraph apparatus, w ich ex cites an auxiliary winding of thetransmitter relay and throws its armature over, whereby the receivingrelay is also chan ed over and a pre-selector switched in. A r thispreselection, which takes place automaticall the subscriber may proceedto select with h1s dial. In order to maintain the connection,

. while the telegraph relay is in its true position of rest or vibratessynchronously with the telegra h or selector impulses, retarding means,suc as slow-acting relays, are employed which, while the armature is inthe false position of rest, are not excited and maintain the circuitclosed for the duration of the connection. The slow-acting relay closesthe circuit of the re-selector for the duration of the connectlon andwhen deexcited releases in well known manner the tripping devices of thepre-selector and the other line selectors.

Two embodiments of my invention are diagrammatically illustrated in thedraw-' ings aflixed hereto and forming part of my specification. In thedrawings,

Fig. 1 is a simplified diagram of connections of an exchange accordingto my invention, and

Fig. 2 is "a diagram of my improved arrangement of relays. I

In "telegraphy various transmitting systems are used. The most importantones are the diplex system (1), the duplex system (2), and theduplex-diplex system (3). All these systems have, however, theresolution in the local circuit in four lines in common, one pair ofwhich transmits messages in one direction and the other pair in the oposite direction. A fifth unsymmetrical con uctor serves only forsecondary purposes of the in-. ternal automatic connection. If theselector afiparatus is thus carried out for four lines,

station by trunk lines L is indicated by the reference letters S or Erespectively. The subscribers station 2 possesses the usual line balanceN.

For sending out selector impulses by the subscriber, there is providedat the subscriber station a number dial D which controls the alternatingcontact at upon operation of the dial and the alternating contact (2upon release of the dial. The contact d operates to disconnect thesending relay S during the selection, from the contact T controlled bythe teletyper ap aratus, and to connect such relay .4 with the impulsecontact d A two-pole reversing switch A is arranged in the circuitofrelay S and has the function of connect-' ing resource of alternatingcurrent B with "relay at thecompletion of a message to efi'ect releaseof the selector. The letter R indicates the receiving magnet of theteletyper apparatus.

- If upon release of the rotated dial D selector impulses are sent tothe automatic exchange by the oscillating movement of the contact d overthe relay S. and the conduit L. the

operating magnet H. at such exchange is intermittently excitedcorresponding to the selector impulses through the medium of the contactZ of the receiving relay E The armature 72. of the magnet H then startsthe selector consisting of five rows of contacts (71, k, Z, m) andcontact brushes. Assuming that three impulses have been dispatched, thebrushes of the selector set themselves on the contacts 3. In the mannerusual in automatic selectors the'connecting through relay P isinstantaneously excited across the row of contacts n and theC-conductors every time one of the contacts 1 to 3 is touched. Sincethis relay P is designed as slow-acting relay,

it only responds when the brush stops on the contact selected.

If the line selected was found to be engaged the relay could notrespond, since the connecting through relay of the occupied selectorwould be connected in parallel to the newly incoming relay, so that inconsequence of the dividing of the current such a weak current only isavailable for each relay, that the armature can be maintained in theattracted position, but cannot be pulled up from the position of rest.

The connecting through relay P now connects the four lines a, b, d, e ofthe selecting stations to the brushes 2', is, Z, m by closing itscontacts P a, P 6, Rd and P e. Since the brushes rest upon the contacts3 and these are in their turn connected to the multiplex lines of thesubscriber 3, the transmission of messages may commence without thetelegraph impulses now sent over the line, which are of the same kind asthe selector impulses, affecting the selectors. This is attained by therelay Q being excited across the closed contact p, f, lines o and c andthe relay Q through the winding of the relay F" whereby its contacts 9and g disconnect the switching magnets H and H of the selectors 1 and 3from the lines a, b of the subscribers connected at the time.

When the communication has come to an end, the double pole switch A,which may be in the form of a key, is temporarily reversed by one of thesubscribers, whereupon the sending relay S is disconnected from thesending and selector contacts and is connected with the source ofalternating current B. The alternating current thus sent out has afrequency different from that of the telegra h fre uencyand brings intoaction, over t e sen ing relay S conductor L and receiving relay E theresonance relay W located in the automatic exchange; the relay W ispermanently connected in these lines and is preferably connected througha condenser C in known manner. The relay W thereupon closes, through itsarmature 'w a circuit for the releasing magnet M which, upon attractingits armature, releases the latching element which holds the selector.The latter then returns to its initial positionunder the infiuenceof aspring; the relays W and P are thus deenergized and the operating magnetH is again connected to the conductors a, I; through g so that themechanism is again in its original position.

Fig. 2 illustrates diagrammatically a relay, in which the resettingdevice of the loaded selectors is released by the application of thefalse position of rest. In this figure W is the winding of a telegraphreceiving relay with the working contact a and the idle contact 1'. Bothcontacts are connected to a pole each of a battery B, the centre ofwhich is grounded.

The armatureof the relay is alternately pulled against one or the otherof the contacts by telegraphic impulses, so that a current ofalternating direction is closed in well known manner. The workingcontact upon which rests the relay during the false idle position isbridged by'the winding V of a slow-acting relay. The slow-acting relaywhose contacts, not shown, control in 'well known manner a pre-selectorand the tripping device of further selectors, is thus short-circuited inthe false idle position of the receiving relay W. \Vhen the receivingrelay is excited its armature is pulled against the true idle contact1", whereby the slow-acting relay is connected to the battery B andexcited. Its contacts complete the pro-selector circuit and alsomaintain it closed during the oscillation of the armature between thecontacts a'and r due to the retarding action. The subscriber afterhaving finished the preselection may thus continue to select with hisdial apparatus and then telegraph. When the transmission is fin shed andthe subscriber sends the clearing impulse over the line. for instance byswitching off his inotor, the armature of the relay W is finally and fora considerable time pulled against the-contact a into the false positionof rest. so that by the dropping oif of the slow-acting relay contactsthe selectors are reset into the initial position and the connection isbroken.

Various modifications and changes may be made without departing from thespirit and the scope of the invention, and I desire, therefore, tha onlysuch limitations shall be placed thereon as are imposed by the priorart.

I claim as my invention:

1. A telegraph or teletyper system comprising a plurality of subscriberstations, lines for transmitting the telegraphic mes sages, one or moreexchanges, automatic selectors at each of said exchanges for connectingsaid stations selectively, means located at the subscriber stat ons andoperative to control the said selectors over the said telegraphiclines', and devices at each of said exchanges for releasing the saidselectors at the end of a communication. said devices being operable bycurrent of a frequency difierent from that of the telegraph currents.

2. A telegraph or teletyper system comprising a plurality of subscriberstations, lines for transmitting the telegraphic messages, one or moreexchanges, automatic selectors at each of said exchanges for connectingsaid stations selectively, means located at the subnance relayresponsive at the frequency of an alternating current transmitted at theend of the communication.

3. A telegraphic or teletyper system comprisin a plurality of subscriberstations, ines or transmitting the telegraphic messages, one or moreexchanges, automatic selectors at each of said exchanges for connect- 5ing said stations selectively, means located at the subscriber stationsand opera ive to control the said selectors over the said telegraphiclines, and devices at each of said exchanges for releasing the saidselectors at the end of a communication, said devices including aresonance relay responsive at the frequency of an alternating currenttransmitted at the end of the communication, said resonance relay beingpermanently connected to said telegraphic lines.

4 A telegraph or teletyper system comprising a plurality of subscriberstations, lines for transmitting the telegraphic messages, one or moreexchanges, automatic selectors at each of said exchanges for connectingsaid stations selectively, means located at the subscriber stations andoperative to control the said selectors over the said telegraphic lines,and devices at each of said exchanges for releasing the said selectorsat the end of a communication, said devices being operable by a currentof the same nature as that of the telegraphic impulses but of durationdifferent from that of said impulses.

5. A telegraph or teletyper system comprising a plurality of subscriberstations, lines for transmitting the telegraphic messages, one or moreexchanges, automatic selectors at each of said exchanges for connectingsaid stations selectively, means located at the subscriber stations andoperative to control the said selectors over the said telegraphic lines,devices at each of said exchanges for releasing the said selectors atthe end of a communication, and a relay forming part of the telegraphingcircuit and having a contact movable between-a false idle position and atrue idle position occupied during the operation of the system, saiddevices being controlled by the contact of said relay in such manner,that the release of said devicesis effected upon switching such contactfrom the true idle position to the false idle position.

6. A telegraph or teletyper system comprising a plurality of subscriberstations,

lectors at each of said exchanges for connecting said stationsselectively, means located at the subscriber stations and operative tocontrol the said selectors over the said tele' graphic lines, devices ateach of said exchanges for releasing the said selectors at the end of acommunication, a polarized relay forming part of the telegraphingcircuit, and a slow-acting relay having a winding bridg ing the contactof the olarized relay, said devices being controlle by said slow-actingrelay.

7 A telegraph or telety or system comprising a plurality of subscri erstations, lines .for transmitting the telegraphic messages,

one or more exchanges, automatic selectors at each of said exchanges forconnecting said stations selectively,--means located at the subscriberstations and operative to control the said selectors over the saidtelegraphic lines, devices at each of said exchanges for releasing'thesaid selectors at the end of a communication, and switching mechanismautomatically cut in at the termination of a communication at asubscriber station, said devices being controlled by said mechanism.

8. A telegraph or telety ersystem comprising a plurality of subscri rstations, lines for transmitting the telegraphic messages, one or moreexchanges, automatic selectors at each of said exchanges for connectingsaid .stations selectively, means located at the subscriber stations andoperative to control the said selectors over the said telegraphic lines,devices at each of said exchanges for releasing the said selectors atthe end of a communication, and automatic switching mechanism in saidsubscriber stations adapted to be cut in when the teletyper apparatus isat rest, said devices being controlled by said mechanism.

In testimony whereof I afiix my signature.

AUGUST J IPP;

